Cheapest is BAL X-Chocks between wheels to stop suspension from moving.
Next would be stabilizers like JT Strongarms or such to stop stabilizer jacks from moving.
Most expensive would be a four point leveling system (aftermarket) to lift/stabilize frame.
2011 Chevy 3500 HD LTZ Duramax/Allison Crew Cab Long Box DRW
B&W Turnover Ball with Companion
2012 Keystone Cougar 293 SAB 5er
USAF 1968 - 1972 Viet Nam '71 - '72